Answer:
Rocks are an abiotic factor because they have never been alive.
An abiotic factor is a non-living component of the ecosystem. The abiotic factor affects the living factors of the ecosystem. The abiotic factors includes sunlight, weather conditions, temperature, water, soil, minerals and other factors.
Rock is a non-living factor of the city park ecosystem. Therefore, statement rocks are an abiotic factor because they have never been alive best illustrates a abiotic factor that is often found in a city park.